<template>
    <el-container class="home-container">
      <!-- 头部区域 -->
      <el-header>
        <div>
          <img src="../assets/heima.png" alt="">
          <span>电商后台管理系统</span>
        </div>
        <el-button type="info" @click="logout">退出</el-button>
      </el-header>

      <!-- 页面主体 -->
      <el-container>
        <!-- 侧边栏 -->
        <el-aside :width="isCollapse ? '64px' : ' 200px'">
        <!-- 侧边栏 菜单区 -->
        <div class="toggle-button" @click="toggleCollapse">|||</div>
        <!-- 侧边栏菜单区域 -->
    <el-menu background-color="#333744" text-color="#fff" active-text-color="#409EFF" unique-opened :collapse="isCollapse" :collapse-transition="false" router :default-active="activePath">

      <!-- 一级菜单UI绘制 左侧菜单  item.id 与字符串拼接会得到字符串 -->
      <el-submenu :index="item.id + '' " v-for="item in menulist" :key="item.id">
        <!-- 一级菜单模版区 -->
        <template slot="title">
          <!-- 图标 -->
          <i :class="iconsObj [item.id]"></i>
          <!-- 文本 -->
          <span>{{item.authName}}</span>
        </template>

        <!-- 二级菜单 UI绘制 左侧菜单通过二层 for循环 将左侧菜单结构渲染出来-->
        <el-menu-item :index="'/' + subItem.path + '' " v-for="subItem in item.children" :key="subItem.id" @click="saveNavState('/' +subItem.path)">
            <template slot="title">
          <!-- 图标 -->
          <i class="el-icon-menu"></i>
          <!-- 文本 -->
          <span>{{subItem.authName}}</span>
        </template>
        </el-menu-item>

      </el-submenu>
    </el-menu>
    </el-aside>
        <!-- 右侧主体 -->
        <el-main>
          <!-- 路由占位符 -->
          <router-view></router-view>
        </el-main>
      </el-container>

    </el-container>
</template>

<script>

export default {
  data () {
    return {
      // 左侧菜单数据
      menulist: [],
      iconsObj: {
        125: 'el-icon-user-solid',
        103: 'el-icon-picture',
        101: 'el-icon-star-off',
        102: 'el-icon-s-order',
        145: 'el-icon-s-goods'
      },
      // 菜单默认不折叠
      isCollapse: false,
      //  被激活的链接地址
      activePath: ''
    }
  },
  created () {
    this.getMenuList()
    this.activePath = window.sessionStorage.getItem('activePath')
  },

  methods: {
    logout () {
      // 清空 在浏览器中存储 key/value 的token值
      window.sessionStorage.clear()
      // 重定向回login页面
      this.$router.push('/login')
    },

    // 获取所有的菜单
    async getMenuList () {
      const { data: res } = await this.$http.get('menus')
      if (res.meta.status !== 200) return this.$message.error(res.meta.msg)
      this.menulist = res.data
      console.log(res)
    },
    // 点击按钮 切换菜单的折叠与展开
    toggleCollapse() {
      this.isCollapse = !this.isCollapse
    },
    // 保存链接的激活状态
    saveNavState(activePath) {
      window.sessionStorage.setItem('activePath', activePath)
      this.activePath = activePath
    }
  }
}

</script>

<style lang="less" scoped>
.home-container {
    height: 100%;
}
.el-header {
  background-color: #373d41;
  display: flex;
  justify-content: space-between;
  padding-left:0 ;
  align-items: center;
  color: #fff;
  font-size: 20px;
  >div{
    display: flex;
    align-items: center;
    span{
      margin-left: 15px;
    }
    img{
      width: 60px;
    }

  }
}

.el-aside {
  background-color: #333744;
  .el-menu{
     border-right:none ;
 }
}

.el-main {
  background-color: #EAEDF1;
}

.el-iconfont {
  margin-right: 10px;
}

.toggle-button{
  background-color: #4A5064;
  font-size: 10px;
  line-height: 24px;
  color: #fff;
  text-align: center;
  letter-spacing: 0.2em;
  cursor: pointer;
}
</style>
